Industrial sweepers of the type having a hopper for the accumulation of dust and debris are well known in the art. A rotating brush sweeps the dust and debris on the floor into the hopper through a hopper inlet located adjacent the brush. An air suction system is also employed to assist in the dust and debris collection by creating a suction air path from the hopper inlet, into the hopper, and through a filter element. The filter element is disposed within the hopper generally proximate the air suction system source.
In on-going efforts to provide more efficient collection of dust and debris, the design of the hopper has evolved from a single open chamber hopper into a multiple-chamber hopper. The multiple-chamber hopper generally consists of a conventional-type hopper subdivided by internal walls or partitions into a main hopper and what is termed a dust box. The dust box may be further subdivided by a wall or partition to thereby define a dirty side and a clean side to the dust box. A filter is generally disposed between the dirty side and the clean side of the dust box, wherein the terms are defined.
The main hopper is designed to accumulate large debris and particles while the dust box is designed to accumulate small debris, dust and particulate matter. This is generally accomplished by creating a tortuous air flow pattern within the hopper. This creates a separating effect for the debris, but only allows the inflow of such debris. Once the main hopper and dust box is full of dust and debris, it must be emptied. This is generally accomplished by raising the hopper up and away from the body of the sweeper through a pivot and hydraulic system. The debris exits from the hopper through the hopper inlet opening when the hopper door is opened upon the hopper reaching the apex of its travel.
In order for the debris and fine particulates to be emptied from the dust box, an outlet opening is disposed in the bottom partition partly defining the dust box. The outlet opening of the dust box is generally remote from the inlet opening to the dust box and is at the lowest point of the dust box in order for the particulate matter to settle over or adjacent the outlet opening.
These prior art hoppers, incorporating separate dust boxes, generally have complicated mechanics and/or hydraulics to maintain the outlet opening of the dust box closed when the sweeper is accumulating debris, and which opens the outlet opening of the dust box during the dumping operation to allow the accumulated debris to fall into the main hopper. From there, the dirt and debris exits the hopper inlet/outlet. Such complicated machinery, installed within a very dirty environment, is subject to complications.
It is therefore an object of the present invention to provide a non-mechanical dust box dumping mechanism.